Kinetics of H2S Sorption on Manganese Oxide and Mn-Fe-Cu Mixed Oxide Prepared by the Complexation Technique

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Pinar Caglayan ◽  
Sena Yasyerli ◽  
Irfan Ar ◽  
Gulsen Dogu ◽  
Timur Dogu
Keyword(s):  
Manganese Oxide ◽  
Mixed Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Hydrogen Gas ◽  
Fixed Bed Reactor ◽  
High Porosity ◽  
Retention Capacity

Hydrogen sulfide sorption activities of manganese oxide and Mn-Fe-Cu mixed oxide sorbents were examined in a fixed bed reactor. Sulfur retention capacity of Mn-O sorbent was found to be quite high at 600 °C both in the absence and presence of hydrogen gas (0.17 and 0.14 g S/g sorbent, respectively). This sorbent has a high porosity and a relatively high surface area. Best regeneration temperature of this sorbent was found as 700 °C, with a gas stream containing 6% oxygen in nitrogen. Mn-Fe-Cu mixed oxide sorbent had a lower sulfur retention capacity (0.07 g S/g sorbent). However, both of these sorbents gave quite high initial sorption rate constants, resulting very sharp breakthrough curves. Deactivation model was shown to give good agreement with the experimental H2S breakthrough curves.

scholarly journals Activity Evaluation of CoMo Nanoparticles Supported on Meso-microporous Composites in Dibenzothiophene Hydrodesulphurization

2019 ◽  
Vol 15 (1) ◽  
pp. 112-118
Author(s):  
Nastaran Parsafard ◽  
Mohammad Hasan Peyrovi ◽  
Zahra Mohammadian ◽  
Niloofar Atashi
Keyword(s):  
Activation Energy ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Ft Ir ◽  
Adsorption Desorption

CoMo-supported mesoporous catalysts were synthesized by 50 wt% of HZSM-5 and 50 wt% of FSM-16, KIT-6, and MCM-48. These catalysts were prepared by the wet-impregnation method and pre-sulfided with CS2. The catalytic performance was evaluated for HDS reaction of dibenzothiophene over a temperature range of 250-400 °C in a micro fixed-bed reactor under atmospheric pressure. The supported CoMo bimetallic catalysts were characterized by XRD, XRF, FT-IR, N2 adsorption-desorption, and SEM. The CoMo/KIT-6/HZSM-5 indicate higher activity than other catalysts at 400 °C for dibenzothiophene hydrodesulphurization. Also, the best selectivity to cyclohexylbenzene (CHB) is related to CoMo/FSM-16/HZSM-5. The activation energy was also calculated for all prepared catalysts for the conversions of less than 10%; according to which, the activation energy for CoMo/KIT-6/HZSM-5 is less than other catalysts (~21 kJ/mol) which can be related to the appropriate pore size and high surface area of the support. Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals Almond Shell as a Microporous Carbon Source for Sustainable Cathodes in Lithium–Sulfur Batteries

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1428 ◽  
Author(s):  
Almudena Benítez ◽  
Marcos González-Tejero ◽  
Álvaro Caballero ◽  
Julián Morales
Keyword(s):  
Coulombic Efficiency ◽  
Electrochemical Behaviour ◽  
High Surface ◽  
Specific Capacity ◽  
High Surface Area ◽  
Microporous Carbon ◽  
High Porosity ◽  
Almond Shell ◽  
Retention Capacity ◽  
Lithium Sulfur Batteries

A microporous carbon derived from biomass (almond shells) and activated with phosphoric acid was analysed as a cathodic matrix in Li–S batteries. By studying the parameters of the carbonization process of this biomass residue, certain conditions were determined to obtain a high surface area of carbon (967 m2 g−1) and high porosity (0.49 cm3 g−1). This carbon was capable of accommodating up to 60% by weight of sulfur, infiltrated by the disulphide method. The C–S composite released an initial specific capacity of 915 mAh g−1 in the Li–S cell at a current density of 100 mA g−1 with a high retention capacity of 760 mAh g−1 after 100 cycles and a coulombic efficiency close to 100%. The good performance of the composite was also observed under higher current rates (up to 1000 mA g−1). The overall electrochemical behaviour of this microporous carbon acting as a sulfur host reinforces the possibility of using biomass residues as sustainable sources of materials for energy storage.

Modeling of chromium (VI) adsorption from aqueous solutions using Jordanian Zeolitic Tuff

2017 ◽  
Vol 75 (9) ◽  
pp. 2064-2071 ◽  
Author(s):  
Reyad Al Dwairi
Keyword(s):  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Size Fraction ◽  
Breakthrough Curves ◽  
Zeolitic Tuff ◽  
Fixed Bed Column ◽  
Grain Sizes ◽  
Chromium Vi

The probable use of Jordanian natural zeolitic tuff in wastewater treatment as natural adsorbent for the removal of Cr (VI) ions from aqueous solution in continuous fixed bed columns was tested experimentally and theoretically. The tested zeolitic tuff was obtained from Al Hala volcano (HZ) located in southern part of Jordan and subjected to crushing and sieving only without any further treatment. Experimentally the HZ grains were packed in a fixed bed column. The used grain sizes are HZ1 (1.0–0.60 mm) and HZ2 (0.60–0.30 mm). The adsorption capacity was evaluated using breakthrough curves and by applying the Thomas and Yoon and Nelson models. The Thomas model analysis of the measured breakthrough curves revealed that the adsorbent HZ2 has a higher adsorption capacity to Cr (VI) ions (56.3 mg/g) than HZ1 (35.5 mg/g). The time elapsed to reach 50% breakthrough was determined by the Yoon and Nelson model. The time to reach 50% breakthrough is 318.78 min and 368.18 min for HZ1 and HZ2, respectively. The research results indicate that the small size fraction (HZ2) is more suitable and effective as adsorbent material than the size fraction (HZ1) due to its high surface area.

Highly stable metal-organic framework UiO-66-NH2 for high-performance triboelectric nanogenerators

2021 ◽  
Author(s):  
Yong-Mei Wang ◽  
Xinxin Zhang ◽  
Dingyi Yang ◽  
Liting Wu ◽  
Jiaojiao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Triboelectric Nanogenerator ◽  
High Porosity ◽  
Chemically Modified ◽  
Metal Organic ◽  
Triboelectric Nanogenerators ◽  
Organic Framework

Abstract The high porosity, controllable size, high surface area, and chemical versatility of a metal-organic framework (MOF) enable it a good material for a triboelectric nanogenerator (TENG), and some MOFs have been incorporated in the fabrication of TENGs. However, the understanding of effects of MOFs on the energy conversion of a TENG is still lacking, which inhibits the improvement of the performance of MOF-based TENGs. Here, UiO-66-NH2 MOFs were found to significantly increase the power of a TENG and the mechanism was carefully examined. The electron-withdrawing ability of Zr-based UiO-66-family MOFs was enhanced by designing the amino functionalized 1,4-terephthalic acid (1,4-BDC) as ligand. The chemically modified UiO-66-NH2 was found to increase the surface roughness and surface potential of a composite film with MOFs embedded in polydimethylsiloxane (PDMS) matrix. Thus the total charges due to the contact electrification increased significantly. The composite-based TENG was found to be very durable and its output voltage and current were 4 times and 60 times higher than that of a PDMS-based TENG. This work revealed an effective strategy to design MOFs with excellent electron-withdrawing abilities for high-performance TENGs.

A high-surface-area La-Ce-Mn mixed oxide with enhanced activity for CO and C3H8 oxidation

2018 ◽  
Vol 105 ◽  
pp. 26-30 ◽  
Author(s):  
Baohuai Zhao ◽  
Rui Ran ◽  
Li Sun ◽  
Zesheng Yang ◽  
Xiaodong Wu ◽  
...  
Keyword(s):  
Surface Area ◽  
Mixed Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Enhanced Activity

scholarly journals Adsorption of Mn2+ from Aqueous Solution Using Manganese Oxide-Coated Hollow Polymethylmethacrylate Microspheres (MHPM)

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dhiraj Dutta ◽  
Jyoti Prasad Borah ◽  
Amrit Puzari
Keyword(s):  
Aqueous Solution ◽  
Manganese Oxide ◽  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Coated Sand

Results of investigation on adsorption of Mn2+ from aqueous solution by manganese oxide-coated hollow polymethylmethacrylate microspheres (MHPM) are reported here. This is the first report on Mn-coated hollow polymer as a substitute for widely used materials like green sand or MN-coated sand. Hollow polymethylmethacrylate (HPM) was prepared by using a literature procedure. Manganese oxide (MnO) was coated on the surface of HPM (MHPM) by using the electroless plating technique. The HPM and MHPM were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Optical and scanning micrographs were used to monitor the surface properties of the coated layer which revealed the presence of MnO on the surface of HPM. TGA showed the presence of 4-5% of MnO in MHPM. Adsorption isotherm studies were carried out as a function of pH, initial ion concentration, and contact time, to determine the adsorption efficiency for removal of Mn2+ from contaminated water by the synthesized MHPM. The isotherm results showed that the maximum adsorption capacity of MnO-coated HPM to remove manganese contaminants from water is 8.373 mg/g. The obtained R 2 values of Langmuir isotherm and Freundlich isotherm models were 1 and 0.87, respectively. Therefore, R 2 magnitude confirmed that the Langmuir model is best suited for Mn2+ adsorption by a monolayer of MHPM adsorbent. The material developed shows higher adsorption capacity even at a higher concentration of solute ions, which is not usually observed with similar materials of this kind. Overall findings indicate that MHPM is a very potential lightweight adsorbent for removal of Mn2+ from the aqueous solution because of its low density and high surface area.

Synthesis and Characterization of Supercapacitor Electrode from Fiber of Borassus flabelifer L by Activation Method

2019 ◽  
Vol 966 ◽  
pp. 444-450 ◽  
Author(s):  
Fandi Angga Prasetya ◽  
Ufafa Anggarini ◽  
Yudha Zakaria ◽  
Rosa Dwi Sasqia Putri
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
High Porosity ◽  
Supercapacitor Electrode ◽  
Nitrogen Gas ◽  
Reduced Graphene ◽  
Higher Temperature ◽  
Constant Heating

Supercapacitor require electrode which has high surface area so that it able to store large amounts of charge. In this study, electrode was synthesized from carbon of Borassus Flabellifer L fiber which was carried out through activation and carbonization processes. Raw material was calcined at 400°C for 4 hours followed by activation with NaOH 1 M. The carbonization was then conducted in Nitrogen gas flowing by temperature variations; 650°C, 750°C, and 850°C with a constant heating rate of 20 °C/min. Based on XRD data, it was shown that the material has formed Reduced graphene Oxide (RGO) which has main peaks at (2θ) 240 and 440 with higher purity in higher temperature. SEM results clarified more pores formation at higher temperature which is mesoporous. Cyclic Voltammetry (CV) test was done to determine the capacitance value. By RGO forming with high porosity, it is suitable for supercapacitor electrode application and CV test has examined that heating of Borassus Flabelifer L fiber at 850°C with 5 mV/s scan rate has the highest specific capacitance by 8.25 F/gram with Energy density is 4.125 watt/gram.

scholarly journals Making an ultralow platinum content bimetallic catalyst on carbon fibres for electro-oxidation of ammonia in wastewater

2019 ◽  
Vol 3 (8) ◽  
pp. 2111-2124 ◽  
Author(s):  
A. M. Pourrahimi ◽  
R. L. Andersson ◽  
K. Tjus ◽  
V. Ström ◽  
A. Björk ◽  
...  
Keyword(s):  
Surface Area ◽  
Bimetallic Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Hydrogen Gas ◽  
Metal Alloy ◽  
Carbon Fibres ◽  
Platinum Content ◽  
Platinum Coating ◽  
Electro Oxidation

Conductive high surface area carbon fibres with a bimetallic copper–platinum coating are used as electrode for electro-oxidation of wastewater ammonia. The metal alloy is presented as a novel inexpensive catalyst for the generation of hydrogen gas.

scholarly journals PENJERAPAN GAS CO HASIL PEMBAKARAN SAMPAH MENGGUNAKAN SORBENT TERMODIFIKASI DALAM REAKTOR FIXED BED

REAKTOR ◽  
2013 ◽  
Vol 14 (3) ◽  
pp. 218
Author(s):  
Mariana Mariana ◽  
Farid Mulana ◽  
Purwana Satriyo
Keyword(s):  
Diatomaceous Earth ◽  
Fixed Bed ◽  
Liquid Waste ◽  
High Reactivity ◽  
Fixed Bed Reactor ◽  
High Porosity ◽  
Dry Process ◽  
Wet Process ◽  
Gas Removal ◽  
Co Gas

ADSORPTION OF CO FROM WASTE COMBUSTION USING MODIFIED SORBENT IN A FIXED BED REACTOR. Gases produced by garbage burning consist of dangerous gases such as CO, SO2 and other gases. Technology for reducing dangerous gases from incinerator outlet can be done by using a dry or wet process. The dry process is more economical process because of simple process, easy maintenance and no liquid waste as product. However, the weakness of the dry process is low absorption conversion and low gas removal efficiency. One way to overcome these problems is to use sorbent which has high reactivity. An inexpensive sorbent that commonly used is Ca(OH)2. The aim of this research was to increase the reactivity of Ca(OH)2 sorbent by using diatomaceous earth and compost as a source of silica and biosorbent, respectively. Diatomaceous earth contains CaO, SiO2 and Al2O3 and compost contains bacteria as a biosorbent that can convert CO to CO2 and CH4. The reaction between SiO2 and Ca(OH)2 would form calcium silicate hydrate (CaO.SiO2.2H2O) that has a high porosity and reactivity. The results showed that the reactivity of Ca(OH)2 sorbent increased by addition of diatomaceous earth and compost. The results also showed that the sorption of CO gas increases with increasing of height of sorbent bed and temperature. The highest CO gas sorption was obtained at temperature of 150oC and sorbent bed height of 6 cm using the modified sorbent with Ca(OH)2/DE/compost ratio of 3:1:1. Gas hasil pembakaran sampah terdiri dari gas-gas yang berbahaya seperti CO, SO2 dan lain sebagainya. Teknologi penghilangan gas-gas tersebut dapat dilakukan dengan menggunakan proses kering maupun proses basah. Penghilangan dengan proses kering lebih ekonomis karena sederhana, mudah pemeliharaan dan tidak menghasilkan limbah cair. Namun demikian, kelemahan proses kering adalah konversi absorpsi rendah dan efisiensi penyisihan  gas relatif kecil. Salah satu cara mengatasi masalah tersebut di atas adalah dengan menggunakan sorbent yang mempunyai reaktifitas yang tinggi. Sorbent yang umum digunakan dan murah adalah Ca(OH)2. Penelitian ini bertujuan untuk meningkatkan reaktifitas sorbent Ca(OH)2 dengan menggunakan tanah diatomeae sebagai sumber silika dan kompos sebagai sumber biosorbent. Tanah diatomea umumnya mengandung CaO, SiO2 dan Al2O3. Reaksi antara SiO2 dengan Ca(OH)2 membentuk kalsium silicate hidrat (CaO.SiO2.2H2O) yang mempunyai porositas dan reaktifitas yang tinggi. Kompos mengandung bakteri sebagai biosorbent yang dapat mengubah gas CO menjadi CO2 dan CH4. Hasil penelitian menunjukkan bahwa reaktifitas sorbent Ca(OH)2 meningkat dengan penambahan DE dan kompos. Hasil penelitian juga menunjukkan bahwa penjerapan gas CO meningkat dengan meningkatnya tinggi unggun sorbent dan temperatur. Penjerapan gas CO tertinggi diperoleh pada penggunaan modifikasi sorbent Ca(OH)2/DE/kompos (3:1:1), temperatur 150oC dan tinggi unggun sorbent 6 cm dari variabel yang dilakukan.

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